There's a link between the theft of a diamond and a boy's stolen dog. March: Boris Karloff. Linda: Doris Nolan. Heather: John Boxer. Sir Nigel: Michael Shepley. Willie: Kid Terrington. Ames: Ewan Roberts. Judge: Eliot Makeham.
A retired officer's sanity is questioned when he claims he saw a murder committed by an "invisible man." March: Boris Karloff. Ames: Ewan Roberts. Major: Anthony Forward. Young Man: Roger Maxwell. Young Woman: Patricia Owens.
A monkey is the only one who can solve the mystery of a scientist's suicide---or murder. March: Boris Karloff. Clarence: Victor Platt. Watkins: Percy Marmont. Nell: Ann Gudrun. Dutch Cook: John Schlesinger. Guy: Richard Burrell. Ames: Ewan Roberts.
While visiting an astronautical scientist, March is confronted with a strange murder. Annette: Rosalie Crutchley. Lavois: Peter Illing. Ames: Ewan Roberts. Rogel: Christopher Rhodes. Philip: Michael Allan.
March's attempt to solve a murder is hindered by a monk's vow of silence. March: Boris Karloff. Ames: Ewan Roberts. Francois: Anton Diffring. Madeleine: Zena Marsh. Philippe: Eugene Decker. Father Mendes: Carl Jaffe. Dupont: Martin Benson. Waiter: Marne Maitland. Guitarist: Stan Watson.
March defends an emotionally disturbed woman accused of murdering a psychoanalyst. Mrs. Cusby: Eileen Erskine. Hayes: Phil Brown. Cusby: Robert Adair. Patten: Gerald Heinz. Mrs. Patten: Lilly Kann. Ames: Ewan Roberts.
Has a fake medium raised a ghost---or is she being doublecrossed? March: Boris Karloff. Mme. Richter: Virginia Downing. Terry/Henry: Tony Wright. Victoria: Genine Graham. Mrs. Fortesque: Dulcie Bowman. Hibbing: Tristan Rawson. Ames: Ewan Roberts.
Novelist Stanley Rune falls over a cliff to his death. Was it accident or murder? March: Boris Karloff. Helen: Rachel Kempson. Hamilton: Philip Friend. Crowder: Lionel Murton. Hocksby: Russell Waters. Ford: John McLaren. Ames: Ewan Roberts.
A mannequin is murdered---and clues indicate that the killer is color-blind. March: Boris Karloff. Jean Pierre: Christopher Lee. Mme. Jean Pierre: Frances Rowe. Darrow: Peter Dyneley. Ames: Ewan Roberts. Fleur: Isabel George.
Colonel March's niece is haunted by her husband's "ghost" after he is reported killed in an air crash. March: Boris Karloff. Gordon: Phil Brown. Ernest: Peter Reynolds. Brandeis: John Laurie. Ames: Ewan Roberts.
When a notorious underworld figure is murdered, suspicion falls on a man heavily in debt. March: Boris Karloff. Ames: Ewan Roberts. Eleanor: Christine Pollon. Herbert: John Chandos. Jerry: Arthur Hill.
A salon owner is murdered and the leading suspect---her daughter-in-law---has a most unusual alibi. March: Boris Karloff. Mrs. Greer: Margaret Halstan. Johanna: Elspeth Gray. Joseph: Neal Arden. Paul: Patrick Hold. Annette: Ruth Shiell. Ames: Ewan Roberts. Housekeeper: Nora Gordon.
Mountain climbers are threatened by a man disguised as the Abominable Snowman. March: Boris Karloff. Mary: Doris Nolan. Osborne: Ivan Craig. Carlmeddy: Olaf Pooley. Narbov: Alex Mango. Ames: Ewan Roberts.
A man confides that he is contemplating murder---and then his wife is killed. March: Boris Karloff. Ridgway: Glyn Houston. Jennifer: Josephine Douglas. Aunt Josephine: Amy Dalby. Butler: Walter Horsbrugh. Ames: Ewan Roberts.
March witnesses a man's seemingly natural death---and then the body disappears! Hastings: Robert Brown. Ames: Ewan Roberts. Marion: Patricia Marmont. Clara: Adrienne Corri. Kane: Lloyd Lamble. Roger: Richard O'Sullivan.
While vacationing on the Riviera, March is persuaded to track down a killer. Mrs. Sargent: Betty Paul. Thoreau: Marne Maitland. Ames: Ewan Roberts. Saleswoman: Ina De La Haye. Waiter: Donald Cashfield.
While investigating a weird case of theft, March stumbles on a diabolical murder. Nancy: Jane Griffiths. Ames: Ewan Roberts. Wesley: John Arnatt. Canasta: Chan Canasta. Garrick: Trader Faulkner. Ned: Anthony Newley.
Mass hypnotism is used to find an eccentric nobleman's killer. March: Boris Karloff. Horton: Patrick Barr. Emily: Ann Hanslip. Jane: Patricia Laffan. George: Basil Appleby. Ames: Ewan Roberts. Walker: Michael Alexander. Minister: Alfred Burke.
Two fencers in a tournament are suspected of robbing and killing a rich widow. March: Boris Karloff. Coron: Eric Pohlmann. Delius: Laurence Payne. Martha: Rachel Gurney. Rene: Paul Hansard. Marcel: Mark Sheldon. Carter: Edward Cast. Charles: Michael Godfrey. Ames: Ewan Roberts.
March investigates the theft of an archaeological treasure from a museum. Ames: Ewan Roberts. Danier: Stuart Lindsell. Evelyn: Helen Cherry. Braden: Joseph Tomelty. Tom: Peter Coke. Guard: Douglas Herald.